Non-magnetic option (“NMO”) antennas mounts are known in the art and are desirable because many standard antennas are designed and manufactured for compatibility with an NMO antenna mount. For example, FIGS. 1A, 1B, 1C, and 1D are perspective, top, bottom, and exploded views of an NMO antenna mount 100 known in the art. As best seen in FIG. 1D, the NMO antenna mount 100 can include a contact pin 110, a barrel 120, a base 130, and a terminal lug 140.
The contact pin 110 can be, for example, gold plated and include a first member 112 contiguous with and disposed adjacent to a second member 114. The first member 112 can include a laterally extending circular member disposed perpendicular to the second member 114, and the second member 114 can include an elongated shaft with first and second ends. The first end can be disposed adjacent to the first member 112, and the second end can include a notch 116.
The barrel 120 can be, for example, plastic and can include a first member 122 contiguous with and disposed adjacent to a second member 124. The first member 122 can include a laterally extending circular member disposed perpendicular to the second member 124, and the second member 124 can include an elongated shaft. A hollow center cylinder disposed within the first member 122 and the second member 124, and the shaft 114 of the pin 110 can fit into the hollow center cylinder of the barrel 120. As best seen in FIG. 1A, the notch 116 of the pin 110 can extend outside of the barrel 120. Similarly, as best seen in FIG. 1B, the first member 112 the pin 110 can extend outside of the barrel 120.
The base 130 can include a first member 132, and a second member 134 connected by a shaft 136. The first member 132 can include a laterally extending circular member disposed perpendicular to the second member 134, and the second member 134 can include a plate 134. A hollow center cylinder 138 disposed in the base 130 can extend through each of the first member 132, the second member 134, and the shaft 136, and the barrel 120 and pin 120 can fit into the cylinder 138. As best seen in FIG. 1A, the notch 116 of the pin 110 and the barrel 120 can extend outside of the second member 134 of the base 130. Similarly, as best seen in FIG. 1B, the first member 112 of the pin 110 and the barrel 120 can extend outside of the first member 132 of the base 130.
The terminal lug 140 can include a first member 142, and a second member 144. The first member 142 can include a washer 142 with an open center portion 146, and the second member 144 can include a channel extending outwardly from a peripheral edge of the first member 142. As best seen in FIG. 1C, the open center portion 146 of the first member 142 can be placed around at least a portion of the plate 134 of the base 130 and the pin 110 and barrel 120 that extends therefrom. The lug 140 can be soldered to a bottom side of the base 130 with solder 145 to secure the lug 140 thereto.
FIG. 1E is a bottom view of a coaxial cable 150 attached to the NMO antenna mount 100. At least a portion of the cable 150 can be stripped to expose the center conductor 152, and the center conductor 152 can be associated with the notch 116 of the pin 110 that extends outside of the barrel 120 and the base 130. Although not seen in FIG. 7B, the center conductor 152 of the cable 150 can be soldered to the pin 110 to secure the cable 150 thereto.
As best seen in FIG. 1A, an exterior circumference of the first member 132 of the base 130 can include threading 135 disposed thereon. An antenna can be attached to the mount 100 by screwing corresponding threading of the antenna onto the threading 135 of the mount 100. When attached to the mount 100 a push pin of the antenna can make contact with the first member 112 of the pin 110 that extends outside of the barrel 120 and the housing 130.
The above-described NMO antenna mount can be used in connection with an automobile, for example, a taxicab, and can be mounted on or in the body of the automobile so that the associated antenna is outside of the automobile. However, there is no protection against vandalism. Therefore, anyone with access to the antenna can simply unscrew the antenna from the mount without disassembling any portion of the antenna mount or the associated automobile.
Therefore, vandal proof antennas have been developed and are also known in the art. For example, FIGS. 2A, 2B, and 2C are perspective, top, and bottom views of a vandal proof antenna mount 200 known in the art. As best seen in FIG. 2A, the vandal proof antenna mount 200 can include a first member 210 contiguous with and disposed adjacent to a second member 220. Both of the exterior circumferences of the first member 210 and the second member 220 can include threading 215 and 225, respectively, disposed thereon.
The first member 210 can include laterally extending circular member disposed perpendicular to the second member 220. As best seen in FIG. 2B, the first member 210 can also include a hollow center cylinder 212 disposed therein, and the hollow center cylinder 212 can include a male connector 214 disposed therein. An antenna can be attached to the mount 200 by screwing corresponding threading of the antenna onto the threading 215 of the mount 200. When attached to the mount 200, a female connector of the antenna can engage the male connector 214 of the first member 210 of the mount 200.
The second member 220 of the antenna mount 200 can include an elongated shaft. As best seen in FIG. 2C, the second member 220 can also include a hollow center cylinder 222 disposed therein, and the hollow center cylinder 222 can include a male connector 224 disposed therein. As best seen in FIG. 2D, a bolt 242 associated with a coaxial cable 240 can be screwed onto the threading 225 of the mount 200. Thus, a female connector of the coaxial cable 240 can engage the male connector 224 of the second member 220 of the mount 200.
To protect against vandalism, the first member 210 of the antenna mount 200 can include a receptacle 230 for receiving a set screw. As best seen in FIG. 2A, the receptacle 230 can be disposed in a bottom side of the first member 210 and can include threading 232 along the length thereof. The receptacle 230 can bore through the first member 210 so that a screw placed in the receptacle 230 can extend from the receptacle on the bottom side of the first member 210 to and past an outside edge of the first member 210. After an antenna is attached to the mount 200 a set screw can be placed in the receptacle 230, and the set screw can be screwed into the antenna from the bottom side of the mount 200 to secure the antenna to the antenna mount 200.
Although vandal proof antenna mounts are desirable to protect against vandalism, these mounts present other disadvantages. For example, as seen in a comparison of FIG. 2A to FIG. 1A, the second member 220 of the vandal proof antenna mount 200 is significantly longer than any part of the NMO antenna mount 100. The length of the vandal proof antenna mount 200 thus limits the applications and environments in which these mounts can be used. For example, known vandal proof antenna mounts have traditionally been used in buses rather than automobiles because the size of these mounts has been incompatible with automobiles.
Additionally, as seen in FIGS. 2B, 2C, and 2D, the vandal proof antenna mount 200 includes non-standard interfaces. For example, the antenna interface of the first member 210 includes the male connector 214. However, the majority of antennas in the marketplace are not designed for such an interface. Further, the antenna interface of the second member 220 includes the male connector 224 and requires a female interface associated with a coaxial cable for connecting thereto as well as extra parts for connecting the female interface of the cable to the male interface of the mount. The extra parts add additional costs and height to the overall system, further limiting the applications and environments in which the mount can be used.
In view of the above, a single antenna mount that is vandal proof and compatible with a majority of antennas in the industry is desired. Preferably, a vandal proof NMO antenna mount in accordance with the present invention can include a standard interface for connecting to an antenna, at least one feature to protect against vandalism, and an interface for connecting a coaxial cable directly to a pin of the antenna mount.